1. Field of the Invention
The present invention relates to a network filtering circuit, and more particularly to a preferable Electromagnetic Compatibility (EMC) and impedance matching circuit network.
2. Description of Related Arts
Chinese Patent No. CN204733134U issued on Dec. 25, 2013, discloses a network filtering circuit including a cable side, a physical side, and a plurality of differential pair transmission channels connected therebetween. Each of the transmission channels includes a CMC (Common Mode Choke) and two Y type capacitors. Each differential pair transmission channel includes a first transmission line and a second transmission line with the aforementioned two Y type capacitors respectively connected within the first transmission line and the second transmission line in series connection. The CMC includes a first coil and a second coil coupled with each other wherein the CMC is closer to the physical side while the two Y type capacitors are closer to the cable side and directly directed to the ground node. The Electro Magnetic Interference (EMI) is derived from the ground line which performs reference potential, If the ground line is improperly designed, the ground potential will be unstable that have the whole network circuits malfunction. The ground line is used for stabilizing the ground potential, thus eliminating the interference. The prior art shows the Y type capacitor is directly linked to the ground node, thus having the first transmission line and the second transmission line tend to receive the EMI from the ground node and affecting the signal transmission.